Pannus in Dogs: Symptoms and Treatment Options

Pannus in dogs, also known as chronic superficial keratitis (CSK), is a permanent and progressive condition of the eye. Left untreated, pannus results in pain, blurred vision, and, ultimately, blindness. Fortunately, pannus is relatively straightforward to diagnose and can be well managed with medication and lifestyle adjustments. 

Whether your pet was recently diagnosed with pannus or you are simply taking preventative measures to protect them, this article covers everything you need to know about pannus in dogs. That way, can recognize the symptoms and understand how dog pannus is treated and managed if your pet is affected by the troublesome disease.

What Is Pannus?

Pannus is a disease where blood vessels and scar tissue progressively invade the cornea. This change usually begins at the outer and lower aspect of the eye, and occasionally, the third eyelid will also be affected. Over time, the entire cornea will become affected, resulting in cloudiness and then darkening known as pigmentation. As the once-clear cornea becomes pigmented and black, light can no longer pass through the cornea and vision is lost. 

The disease affects both eyes, although not always symmetrically, meaning that one eye might begin earlier than the other. 

Causes of Pannus in Dogs

Pannus in dogs is believed to be a genetic, immune-mediated condition. Increased exposure to ultraviolet light, high altitudes, and smoke are considered predisposing factors for the development of pannus. These factors can also exacerbate pannus and make it harder to treat. 

German Shepherds and German Shepherd mixes are the most commonly affected breed. Other breeds that are prone to pannus include Greyhounds, Rottweilers, Belgian Tervuren, and Border Collies. Any breed, however, can develop pannus. 

In most cases, pannus develops in dogs between 4 and 7 years of age. Generally, the earlier a dog develops pannus, the more severe the case tends to be. Cases of pannus that develop after dogs are 5 or 6 tend to be more responsive to treatment and easier to manage. 

Symptoms of Pannus in Dogs

Dogs with pannus often display one or more of the following symptoms:

• A raised red lump on the eye
• A grayish-pink film on the eye
• Visible blood vessels on the eye
• Dark brown pigmentation of the eye
• Excess tearing of the eye
• Pawing or rubbing at the affected eye
• Poor vision (running into walls, reluctant to jump or play, etc.)

It’s important to keep in mind that blindness is an end-stage result of untreated pannus. Early pannus in dogs does not typically result in signs of blindness. 

Diagnosing Pannus in Dogs

Pannus in dogs is usually diagnosed by a thorough history and veterinary physical exam. However, your veterinarian will need to perform a series of tests on the eye, such as a fluorescein stain, a Schirmer Tear Test, and measurement of intraocular pressures. These tests are mainly to rule out other common dog eye diseases and help guide your veterinarian in creating the best treatment plan for your pet. 

How to Treat Pannus in Dogs

While pannus in dogs cannot be cured, it can be well managed with topical medications. The goal of treatment is to stop the progression of the corneal pigmentation and preserve vision. 

An anti-inflammatory and immunosuppressive steroid, such as dexamethasone, is often prescribed either alone or with an immune-modulating drug, such as cyclosporine. These are administered directly to the affected eye(s) either as drops or as ointment. Initially, the drops will be given frequently throughout the day. As the pannus improves, the medications can be tapered down to twice daily. 

In severe cases of pannus, or those that fail to respond to topical medications, steroid injections can be made directly into the eye. This is usually reserved for extreme cases and should only be done by a skilled veterinarian or veterinary ophthalmologist.

How to Prevent Pannus in Dogs

Whether you’re trying to prevent a flare up of pannus in your dog, or trying to prevent your dog from developing pannus, there are a few cautionary measures you can take. Since ultraviolet light, high altitudes, and smoke can exacerbate or induce pannus in dogs, pet owners should try to avoid exposing their dog to these elements, especially in German Shepherds or other breeds predisposed to pannus. 

Dogs can be kept indoors during the sunniest part of the day, and when they are outside, they should have adequate shelter and shade. Shaded walking trails and parks with trees are good options for exercise.

You should never smoke cigarettes around your dog, especially in areas with poor ventilation, and dogs should be kept a safe distance away from campfires or fire pits. 

Lastly, trying a specialty pair of canine sunglasses, such as RexSpecs or Doggles, can help prevent light exposure and protect your dog’s eyes from developing pannus or a relapse of pannus.